DE29915093U1 - Device for establishing the equipotential bonding in cable routing channels - Google Patents

Description

PATENT ATTORNEYS DIPL.-ING. F. W. MOLL · DIPL.-ING. H.CH. BITTER ADMISSIONABLE REPRESENTATIVES BEFORE THE EUROPEAN PATENT OFFICE LANDAU/PALATINATE

27.08.1999 B/Co.

Tehalit GmbH, 67716 Heltersberg

Device for establishing potential equalization in cable ducts

CORRESPONDENCE OFFICE BANK DETAILS

P.O. Box 2080 ;··. ;··· .·*.\(&iacgr;&iacgr;9&phgr;&idiagr;&&idiagr;6·&ngr; .: :*** .·*. .·*. ""DEUTSCHiBAffc AG LANDAU

D-76810 LANDAU/PFALZ · J··· · »-768e9»LANOAU/PJALi·· _# JJ*..! *.O215J 0OpLZ J46 700 95)

TELEGRAM INVENTION FAX 0 63 41 / 2 03 56 275 62-676 (bank code 545 100 67)

Description:

The invention relates to devices for establishing potential equalization between the lower part and the cover of cable guide ducts made of light metal according to the preamble of claim 1.

Cable routing ducts made of light metal, comprising a base and at least one cover, the base and cover being provided with corresponding locking profiles that enable detachable fastening between the cover and base, are in use worldwide in large quantities and for a long time. Depending on the customer's wishes, the surfaces are bare, anodized, painted or powder-coated.

To ensure electrical safety, all components of metal cable ducts that a user could touch must be earthed. For this purpose, all components of commercially available cable ducts are equipped with connections that are connected to one another via equipotential bonding lines. In the case of aluminum cable ducts, these earthing connections are always made separately and attached to the duct elements either in the factory or on site. Care must be taken to ensure that insulating surface layers, including the oxide layer that forms on bare aluminum, are penetrated. The equipotential bonding lines must then be installed on site. This involves considerable effort.

There has therefore been no lack of attempts to achieve the prescribed potential equalization in other ways. The current state of the art involves using auxiliary parts made of sheet steel that are attached to the duct base or duct cover. These auxiliary parts are equipped with sharp edges and/or points that cut through the surface coatings of the duct base and cover, thus establishing the electrical connection.

DE-U 90 12 163, for example, shows such an auxiliary element. This has a foot with which it can be removably attached to a top-hat rail provided on the bottom of the duct. The head of the contact element is a sharp edge that rests against the underside of the cover when it is put on, thus establishing electrical contact. This

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The design may still produce a sufficiently low-resistance connection on bare surfaces; however, if the surfaces are anodized, painted or powder-coated, an electrical connection will certainly not be established.

Other contact elements for ducts made of sheet steel are known from DE-A 197 37 893 or EP-B 0 469 457. These contact elements create the connection between the duct base and the cover in the area of the locking profiles. They are not intended for cable routing ducts made of light metal.

The problem associated with the prescribed equipotential bonding is exacerbated if the bottom of the duct is not closed with just one cover, but with two or three covers, for example, which then have to be earthed individually. In this case, it is often forgotten to connect all the covers to each other and to the bottom of the duct via equipotential bonding lines, which puts the user of such a cable duct at risk.

The present invention is therefore based on the object of specifying devices for establishing potential equalization between the lower part and one or more covers of cable guide ducts made of light metal, which are designed in such a way that the electrical connection between the duct lower part and the cover required for potential equalization is always established when the cover is placed on the lower part.

This object is achieved by a device having the features of claim 1.

The contact device according to the invention uses two types of feet, namely holding feet and contact feet. The holding feet have the task of fixing the contact device in the channel base. The contact feet have the task of establishing the low-resistance contact with one of the holding strips provided on the bottom of the channel base. They should also hold the contact device in the correct, preferably vertical position to the bottom of the channel base. Thanks to this separation of functions, each type of foot can be optimized for its respective function without compromise. This applies in particular to the contact feet.

The electrical contact is also made in the area of the cover in a similar way. The contact device also has sharp edges and/or points in the cover area, which dig into the contact profile when the cover is put on, piercing the insulating surface coating. However, the head of the contact device is designed in such a way that the cover can be removed and replaced at any time if necessary without causing damage.

In contrast to the previously known contact elements, the device according to the invention is not springy but rigid. This ensures that the insulating surface layers are actually penetrated.

According to a further development of the invention, the U-shaped recess in the head of the contact device according to the invention is bevelled in a funnel shape. This makes it easier to put on the cover.

According to a first embodiment of the invention, the closure profile of the cover is also used as a contact profile. This has the advantage that the contact device according to the invention can also be retrofitted in cable routing ducts that have already been installed.

According to a preferred embodiment, the U-shaped recess simultaneously engages and contacts the closure profiles of two adjacent lids.

According to an alternative embodiment, a special contact strip is formed on the underside of the cover. The position of this contact strip can be adjusted to the position of the retaining strips in the lower part of the duct.

In the simplest version, the contact strip is a flat strip into whose side walls the sharp tips of the U-shaped recess dig in. According to a further development, the contact strip has a T-shaped cross-section, for example adapted to the T-shaped cross-section of the retaining strips in the lower part of the duct.

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According to a preferred development of the invention, support surfaces for the lid or its closure profiles are provided on the head of the punched-bent part. Thanks to this feature, the lids are always in the correct position.

In the event that conventional equipotential bonding lines are also to be used, a flat plug is cut out in the base plate of the contact device according to the invention, onto which the equipotential bonding lines are plugged.

Preferably, the contact device according to the invention has two pairs of contact feet so that they can bridge the joint between adjacent channel sections and thus ensure continuous potential equalization.

Advantageously, the contact device is made of corrosion-protected sheet steel.

The invention will be explained in more detail in the form of an embodiment with reference to the drawing.

Fig. 1 a contact device as front view,

Fig. 2 the contact device of Fig. 1 as a plan view

Fig. 3 is a section along the line III-III through the contact device of Fig. 1,

Fig. 4 a cross-section through a cable guide channel with inserted first contact device,

Fig. 5 purely schematically a plan view of a channel formed from three channel elements

Cable duct,
Fig. 6 a cross-section through a cable guide channel with inserted second contact device,

Fig. 7 a cross-section through a cable guide channel with inserted third contact device,

Fig. 8 shows detail VIII from Fig. 7 in an enlarged view, Fig. 9 shows detail IX from Fig. 7 in an enlarged view and Fig. 10 shows an embodiment modified compared to Fig. 9.

Fig. 1 as a view, Fig. 2 as a plan view and Fig. 3 as a section along the line III-III show a first contact device 30 with the aid of which the low-resistance potential equalization between the lower part and the cover of a cable guide channel 10 (Fig. 4) made of light metal can be produced. This is a stamped and bent part made of sheet steel with a base plate 31. At the lower end of the base plate 31 there are two pairs of holding feet 34, 35 and two pairs of contact feet 32. The holding feet 34, 35 fix the contact device 30 to the lower part of the channel (Fig. 4) or to the holding strips 14, 15 provided there.

The contact feet 32 are equipped with sharp edges and/or points that dig into one of the retaining strips 14, 15 on the floor 11 of the channel base and thus create the desired low-resistance connection. In addition, they define the correct position of the contact device 30 to the channel base.

At the upper end of the base plate 31, two head parts 37 can be seen, each with a U-shaped, funnel-shaped beveled recess 36. The recess 36 has sharp edges which dig into the contact profile of a cover when it is placed on top, thus creating the required low-resistance connection.

As can be seen from Fig. 1, a flat plug 38 is formed in the base plate 31 by means of a three-sided cut-out, onto which conventional potential equalization cables with corresponding plug devices can be plugged.

Fig. 4 shows a cross section through a cable routing channel 10 with the first contact device 30 inserted. The channel lower part consists of a base 11 and two side walls 12, at the upper end of which closure profiles 13 are provided. The open side of the channel lower part 11, 12, 13 is closed with three covers 16, 17, 18.

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Retaining strips 14, 15 are provided on the inside of the base 11. The contact device 30 is plugged onto one of the retaining strips 15. Thanks to the contact feet 32 supported on the channel base 11, the contact device 30 is always vertical. As a result, its head-side recess 36 is aligned with the locking profiles 19 of the covers 16, 18, which simultaneously fulfill the function of the contact profile, so that the covers 16, 18 can be placed on and the low-resistance contacts can be made without any problems.

Fig. 5 shows a purely schematic plan view of a cable routing channel made from three channel sections 10.1, 10.2, 10.3. Some of the contact devices 30 are arranged in such a way that they bridge the joint between two adjacent channel sections 10.1, 10.2; 10.2, 10.3, so that the prescribed potential equalization is ensured over the entire length of the cable routing channel.

Fig. 6 shows a cross section through a cable guide channel 10' with a second contact device 40 inserted. This differs in the area of the head 47 in that two U-shaped recesses 46 are provided, each adapted to the cover holding profile 19 of the two covers 16, 17. In addition, special cover holding surfaces 48 are formed on the head 47, on which the cover holding profiles 19 sit, so that the covers 16, 17, 18 always assume their correct position.

Fig. 7 shows a cross section through a cable guide channel 10' with a third contact device 50 inserted. Its foot area is designed in such a way that it interacts with the C-shaped retaining strip 14 on the floor 11 of the channel bottom section. The sharp edges of the contact feet 52 dig into the retaining strip 14. The retaining feet 53, 54 spread out under the retaining strip 14 and permanently fix the contact device 50 to the channel bottom section. Details can be seen in the enlarged illustration in Fig. 8.

A flat strip 20 is formed as a special contact profile on the underside of the cover 16'. The U-shaped recesses 56 in the head 57 of the contact device 50 dig into the side walls of the flat strip 20 and thus establish the low-resistance electrical connection. Details can be seen in the enlarged illustration in Fig. 9.

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Fig. 10 shows a detail of a contact profile 21 with a T-shaped cross-section on the underside of the cover 16', approximately corresponding to the T-shaped retaining strip 15 on the bottom of the duct lower part.

Claims (11)

1. Device for establishing the potential equalization between the lower part ( 11 , 12 , 13 , 14 , 15 ) and at least one cover ( 16 , 16 ', 17 , 18 ) of cable guide channels ( 10 , 10 ') made of light metal, essentially comprising - a stamped and bent part made of sheet steel ( 30 , 40 , 50 ), - with a base plate ( 31 , 41 , 51 ), - with a foot part which corresponds to a retaining strip ( 14 , 15 ) on the bottom ( 11 ) of the channel ( 10 , 10 '), - and with a head part corresponding to the lid ( 16 , 16 ', 17 , 18 ), - wherein the punched-bent part ( 30 , 40 , 50 ) electrically contacts the lower part and the cover of the channel ( 10 , 10 '), characterized by the features: - the punched-bent part ( 30 , 40 , 50 ) has at least - a contact foot ( 32 , 42 , 52 ) whose sharp edges dig into the retaining strip ( 14 , 15 ), - and a head part ( 37 , 47 , 57 ) with at least one U-shaped recess ( 36 , 46 , 56 ), the sharp edges and/or tips of which dig into a contact profile ( 19 , 20 , 21 ) of the cover ( 16 , 16 ', 17 , 18 ). 2. Device according to claim 1, characterized by the feature: - the punched-bent part ( 30 , 40 , 50 ) has a pair of holding feet ( 34 , 35 ; 44 , 45 ; 54 , 55 ) which fix the punched-bent part ( 30 , 40 , 50 ) to the holding strip ( 14 , 15 ). 3. Device according to claim 1, characterized by the feature: - the U-shaped recess ( 36 , 46 , 56 ) is bevelled in a funnel shape. 4. Device according to one of claims 1 to 3, characterized by the feature: - the closure profile ( 19 ) of the cover ( 16 , 16 ', 17 , 18 ) forms the contact profile. 5. Device according to claim 4, characterized by the feature: - the U-shaped recess ( 36 ) holds and contacts the locking profiles ( 19 ) of two adjacent covers ( 16 , 18 ). 6. Device according to one of claims 1 to 3, characterized by the feature: - a special contact strip ( 20 , 21 ) is formed on the underside of the cover ( 16 '). 7. Device according to claim 6, characterized by the feature: - the contact strip ( 21 ) has a T-shaped cross-section. 8. Device according to one of claims 1 to 7, characterized by the feature: - on the head ( 47 , 57 ) of the punched-bent part ( 40 , 50 ) support surfaces ( 48 , 58 ) for the lid ( 16 , 16 ', 17 , 18 ) or its closure profiles ( 19 ) are provided. 9. Device according to claims 1 to 8, characterized by the feature: - a flat plug ( 38 ) is cut out in the base plate ( 31 ). 10. Device according to one of claims 1 to 9, characterized by the features: - the stamped and bent part ( 30 ) has at least two contact feet ( 32 , 42 , 52 ), - the contact feet ( 32 , 42 , 52 ) bridge the joint between adjacent channel sections ( 10.1 , 10.2 , 10.3 ). 11. Device according to one of claims 1 to 10, characterized by the feature: - the punched and bent part ( 30 ) is made of stainless steel sheet.